Mark DeCarlo

as Hugh Neutron / Octopus Man (voice)

Billy West

as Sam Melnick / Man (voice)

Andrea Martin

as Ms. Fowl (voice)

Megan Cavanagh

as Judy Neutron (voice)

Carolyn Lawrence

as Cindy Vortex (voice)

Crystal Scales

as Libby Folfax (voice)

Frank Welker

as Goddard / Special Vocal Effects (voice)